When transporting a steel strip coil manufactured in a steel works from the steel works to a customer, it is necessary to package the coil to prevent flaws or rust from occurring on the coil and dust from depositing thereon. When transporting a steel strip coil by sea, in particular, the coil must be doubly packaged with the use of water-proof paper and a thin steel sheet.
An example of the process in the case where the coils doubly packaged as described above are transported from a steel works in Japan to Chicago or Detroit in North America is described below.
The thus doubly packaged coils are transported from a steel works to a bonded warehouse near a shipping port, and piled up into a plurality of piles in the bonded warehouse for storage. When a cargo ship arrives, coils to be loaded on the cargo ship are selected from among the coils stored in the bonded warehouse. The thus selected coils are transported to a wharf and temporarily placed there. Then, the coils placed on the wharf are hoisted up by means of a crane, transferred into holds of the cargo ship, and piled up into a plurality of piles in the holds. The thus piled coils are firmly fixed to each other by means of ropes.
The cargo ship loaded with the piled coils departs from the shipping port, passes through the Panama Canal, and reaches the Great Lakes in North America in summer, or reaches the east coast of North America in winter. In either of the above areas, the coils are unloaded from the cargo ship. The unloaded coils are put on a special wagon for coils and transported on this special wagon by rail to Chicago or Detroit which is the final destination.
The conventional packaging and transportation of the coils as described above, have the following problems:
(1) The necessity of double packaging of the coil with the use of water-proof paper and a thin steel sheet requires much labor, time, materials and cost for packaging.
(2) Since loading, unloading and transportation of the coils are carried out a plurality of times as mentioned above during transportation of the coils from the steel works to the final destination, flaws may easily occur on the coils during handling thereof.
(3It is not easy to select coils to be loaded on the cargo ship from among the coils stored in piles in the bonded warehouse and to transport the thus selected coils to the wharf.
(4) When it rains, it is necessary to discontinue transportation of the coils from the bonded warehouse to the wharf and loading of the coils from the wharf on the cargo ship, and to cover the coils on the wharf with a water-proof sheet, thus considerably reducing the handling operation efficiency.
(5) Stabilization of the coils piled up into a plurality of piles in the bonded warehouse or in the holds of the cargo ship, requires many stoppers corresponding to the coil size, and the coils piled up into a plurality of piles in the holds of the cargo ship must be fixed to each other by means of ropes in a large quantity.
(6) When the cargo ship on the voyage suffers from stormy weather or rough sea, the ropes fixing the coils piled up into a plurality of piles in the holds loosen and the coils hit each other, causing flaws on the coils. When rolling and pitching of the cargo sip is serious, furthermore, the ropes fixing the coils may be broken and the released coils may be scattered about in the holds, resulting in the impossibility of gathering them.
(7) In order to transport the unloaded coils on land, it is necessary to use a special wagon for coils, and to transport them by rail. The quantity of transported coils is therefore limited.
(8) When transporting the coils from Japan to Chicago or Detroit, for example, the coils must be transported by sea, as described above, from a shipping port in Japan to the Great Lakes or the east coast of North America on a cargo ship, and then transported by rail to the destination. Until the coils reach the destination, therefore, sea transportation takes about 32 days, and land transportation, about 4 days, requiring a long period of time of about 36 days in
total. As a result, coils in a prescribed quantity
cannot sometimes be delivered to the customer on or
before a prescribed delivery date.
(9) If the coils get wet by rainfall, for example, during handling or transportation thereof, rust may occur on the coils.
Under such circumstances, there is a strong demand for the development of a container for housing a metal strip coil, which permits simplification of packaging of the coil, prevents flaws or rust from occurring on the coil during handling or transportation thereof, allows handling of the coil even in the rain, enables land transportation of the coil without using a special wagon for coils, makes it possible to increase the coil transporting efficiency, and particularly does not require the above-mentioned double packaging of the coil, but a container provided with such properties has not as yet been proposed.